Erdafitinib, also known as JNJ-42756493, is a potent and selective orally bioavailable, pan fibroblast growth factor receptor (FGFR) inhibitor with potential antineoplastic activity. Upon oral administration, JNJ-42756493 binds to and inhibits FGFR, which may result in the inhibition of FGFR-related signal transduction pathways and thus the inhibition of tumor cell proliferation and tumor cell death in FGFR-overexpressing tumor cells. FGFR, upregulated in many tumor cell types, is a receptor tyrosine kinase essential to tumor cell proliferation, differentiation and survival.